CN115436803A

CN115436803A - Motor running state detection device and method based on higher harmonic electromagnetic radiation

Info

Publication number: CN115436803A
Application number: CN202211126145.7A
Authority: CN
Inventors: 陆犇; 张宙; 黄翊圣
Original assignee: Shanghai Electric Group Shanghai Electric Machine Works Co ltd
Current assignee: Shanghai Electric Group Shanghai Electric Machine Works Co ltd
Priority date: 2022-09-16
Filing date: 2022-09-16
Publication date: 2022-12-06

Abstract

The invention relates to a motor running state detection device and method based on higher harmonic electromagnetic radiation, wherein a comparison antenna is arranged in the direction vertical to 90 degrees of a sampling antenna, the sampling antenna collects motor electromagnetic signals, then the levels of non-contact signals and contact signals are converted into mV levels through a signal conditioner, the mV levels and the environment background electromagnetic radiation signals received by the comparison antenna enter a short wave radio together, the signals are demodulated and differentially coupled, the signals are converted into analog sound signals, the analog sound signals are output to a loudspeaker through a power amplifier to generate sound prompt of specific frequency, and the on-off and rotating speed change of a motor are qualitatively and visually known according to the tone and size of the sound; or the short wave radio inputs the signal into the embedded singlechip to carry out operation, and one part of the signal is converted into a digital signal through the analog-to-digital converter and is transmitted to the liquid crystal display screen to carry out frequency and intensity parameter display; the other part is uploaded to a quality inspection platform by using WIFI and Bluetooth through a wireless transmitter or is connected with a wireless earphone for use.

Description

Motor running state detection device and method based on higher harmonic electromagnetic radiation

Technical Field

The invention relates to a motor running state detection device, in particular to a motor running state detection device and method based on higher harmonic electromagnetic radiation.

Background

At present, a professional test system or a DCS system and the like are generally adopted to detect various parameter indexes in a motor test, various voltages, currents, resistance meters or sensors and the like are used in the processes of motor maintenance, maintenance and the like, so that the motor test system has the problems of various devices, frequent switching and inconvenience in use, measuring instruments, sensors and the like are mostly required to be connected into a motor driving or controlling system, wires, sensors, chips and the like are required to be manually assembled and disassembled, the operation is complex, the detection efficiency is low, the original use environment of the motor can be damaged, the fault analysis is inaccurate, other unstable factors are introduced and the like; on the other hand, the existing relatively advanced motor remote operation and maintenance system has a relatively low overall installation ratio due to relatively high cost, and particularly, the popularization degree of the conventional motor is far from sufficient. Therefore, a portable handheld diagnostic device capable of quickly determining the operating state of the motor without disassembling the motor and without contact (or external contact) is needed.

In industrial and living environments, when a motor of equipment is electrified and operated, particularly when frequency conversion or PWM (pulse width modulation) driving control is adopted, current in a coil can not only generate an alternating magnetic field, but also emit electromagnetic radiation outwards, so that interference on a radio signal can be frequently generated, the interference can be actively avoided under general conditions, and the interference and noise generated by the motor on the radio can be prevented by adopting methods such as shielding or remote control.

The invention uses the reverse thinking to realize the non-contact detection of the motor running condition by utilizing the characteristic. In actual industrial application, the precision and the discrimination which cannot meet the equipment detection requirements can be realized only by using a common radio circuit, so that a method and a device for differential coupling identification of the double-directional antenna are innovatively designed, and a frequency multiplication principle of Fourier series expansion of electromagnetic radiation is utilized to collect electromagnetic harmonic signals with higher frequency, so that the electromagnetic noise signals caused by the surrounding environment are avoided being annihilated, the detection range is further shortened, and the detection accuracy is improved.

Disclosure of Invention

The invention provides a device and a method for detecting the running state of a motor based on higher harmonic electromagnetic radiation, which can quickly determine the running state without disassembly in the scenes of motor test, maintenance, overhaul and the like, improve the working efficiency and reduce the detection workload; the device is a portable handheld diagnostic device.

In order to achieve the purpose, the technical scheme of the invention is as follows: a motor running state detection device based on higher harmonic electromagnetic radiation comprises a sampling antenna and a comparison antenna, wherein the comparison antenna used for receiving an environmental background electromagnetic radiation signal is arranged in a direction perpendicular to 90 degrees of the sampling antenna, the level of the non-contact signal and the level of the non-contact signal are converted into mV level through a signal conditioner after the sampling antenna collects the motor electromagnetic signal, then the level of the non-contact signal and the level of the non-contact signal are converted into mV level together with the environmental background electromagnetic radiation signal received by the comparison antenna, the mV level and the environmental background electromagnetic radiation signal enter a short-wave radio for demodulation and differential coupling, a higher harmonic signal collection point is converted into an analog sound signal, the analog sound signal is output to a loudspeaker through a power amplifier to generate a sound prompt with specific frequency, and the on-off and rotating speed change of a motor are qualitatively and visually known according to the tone and size of the sound; or the short wave radio inputs the signal into the embedded singlechip to carry out operation, and one part of the signal is converted into a digital signal through the analog-to-digital converter and is transmitted to the liquid crystal display screen to carry out frequency and intensity parameter display; the other part is uploaded to a quality inspection platform by using WIFI and Bluetooth through a wireless transmitter or is connected with a wireless earphone for use.

Further, the parameters of the comparison antenna and the sampling antenna are the same, and comprise fixed frequency, signal gain and orientation angle.

Further, the motor operation state detection device further includes:

a front housing and a rear housing;

the main display screen is a digital display area and is used for displaying signal intensity and signal frequency or outputting motor state parameters after calculation according to the motor parameter characteristics;

the display screen is a simulation display area and qualitatively displays the signal intensity or the voltage level;

the auxiliary cancel key and the confirm key are matched with the display screen for touch control, are used for switching various functions and improve the use stability;

the power switch is a main power switch of the detection device;

a horn cover, the opening of which releases sound;

the frequency modulation knob is used for adjusting the sampling frequency through rotation;

and the gain knob is used for adjusting the signal to noise ratio and the sound size.

Further, the front shell and the rear shell are made of engineering plastics, rubber or nonmetal materials except the engineering plastics and the rubber and are used for preventing the comparison antenna from receiving external signals.

Further, preceding shell and back shell pass through the whole casing of fixed screw connection, set up the battery lid on whole casing back and conveniently change the battery, go out sound hole and hole of falling to in the top and bottom setting back, and the below sets up data and charges the mouth.

Further, the data and charging port is used as an interface for USB wired data transmission, and a rechargeable lithium battery is charged at the same time.

A motor running state detection method based on higher harmonic electromagnetic radiation is adopted, firstly, in an industrial environment, a sampling antenna and a comparison antenna are close to a measured motor in operation, obtained sampling signals of each frequency of the sampling antenna and the comparison antenna are subjected to differential comparison through a logic circuit to carry out in-phase comparison on the two signals, the amplitude of the frequency spectrum of the comparison antenna is subtracted from the corresponding frequency of the frequency spectrum of the sampling antenna, and a differential coupling frequency spectrum is obtained, wherein the differential coupling voltage identification point with the maximum amplitude is the most relevant signal point in the motor running.

Further, in the above process, the detection device is moved to further check whether interference signals of the adjacent motors exist; and selecting a short wave frequency region with higher frequency, and acquiring higher harmonic signal acquisition points with higher frequency and secondary signal amplitude by using a frequency multiplication sampling principle that on-off type step signal electromagnetic radiation is expanded on a corresponding Fourier integer order, so as to avoid a radio noise region.

Further, when used indoors, a radio silence above the radio noise cutoff frequency is selected.

Furthermore, when the device is used in an outdoor field, the top end of the sampling antenna is provided with a metal conductive material or is directly contacted with a metal exposed part of the motor, and the electromagnetic signal of the motor is directly measured by a detection device and a motor shell potential method, so that the function of knowing the running state of the motor without disassembling the motor is achieved.

The beneficial effects of the invention are:

the invention innovatively designs a device and a method for differential coupling identification of the double-directional antenna, and collects electromagnetic harmonic signals with higher frequency by using a frequency doubling principle of Fourier series expansion of electromagnetic radiation, thereby avoiding electromagnetic noise signal annihilation caused by the surrounding environment, further reducing the detection range and improving the detection accuracy.

On the basis of the core principle, detection data can be displayed more visually through a series of circuits and an embedded system, the handheld design is convenient to move and use, meanwhile, the data can pass through mass transfer detection digital platforms such as WIFI and Bluetooth, connecting lines are used as edge sensors, functions of the device are further integrated, meanwhile, a professional and expensive spectrum analyzer device is not adopted, the product cost is quite low, and the handheld spectrum analyzer is suitable for popularization and use.

Drawings

FIG. 1 is a schematic diagram of dual directional antenna differential coupling identification;

in FIG. 1: m-running motor, T-electromagnetic field radiation schematic, A1-sampling antenna, A2-comparison antenna; FIG. 2 is a schematic diagram of a differential coupling identification spectrum;

in FIG. 2: C-A1-sampling an antenna spectrum, C-A2-comparing the antenna spectrum and delta U-peak-differential coupling voltage identification points;

FIG. 3 is a diagram of the Fourier series expansion frequency multiplication principle of electromagnetic radiation;

in FIG. 3: delta U-peak-differential coupling voltage identification point, uac-higher harmonic signal acquisition point, LW-long wave frequency region, MW-medium wave frequency region, SW-short wave frequency region, noise zone-radio noise region, clean zone-radio silence region, F0-radio noise cut-off frequency;

FIG. 4 is a schematic diagram of the internal structure of the detecting unit;

in fig. 4: a1-a sampling antenna, A2-a comparison antenna, a B-signal conditioner, a C-short wave radio, a D-power amplifier, an E-chargeable lithium battery, an F-data and charging port, a G-horn, an H-liquid crystal display screen, a J-analog-to-digital converter, a K-embedded singlechip and an L-wireless transmitter;

FIG. 5 is a schematic diagram of the external structure of the detecting unit;

in FIG. 5: (a) is the front side and (b) is the back side; 1-sampling antenna A1, 2-main display screen, 3-auxiliary display screen, 4-cancel key, 5-power switch 6-horn cover, 7-frequency modulation knob, 8-gain knob, 9-confirm key, 10-front shell, 11-fixing screw, 12-battery cover, 13-rear shell, 14-data and charging port F, 15-rear sound outlet hole and inverted hole.

Detailed Description

The invention is further described with reference to the following figures and examples.

The invention innovatively designs a 'differential coupling identification' device and a method of a bi-directional antenna, as shown in figure 1, in an industrial environment, a sampling antenna A1 of equipment is close to a measured motor M in operation, and the motor M emits electromagnetic field radiation T outwards at the moment, so that the electromagnetic induction intensity is maximum and the signal receiving effect is best because the sampling antenna A1 is parallel to the electromagnetic field radiation T. However, at this time, the air is full of electromagnetic radiation of other devices, broadcasting stations and universe celestial bodies, in order to improve the contrast and accuracy of sampling, a comparison antenna A2 is arranged in the direction perpendicular to 90 degrees of the sampling antenna A1, parameters of the comparison antenna A2 are completely consistent with those of the sampling antenna A1, the comparison antenna includes fixed frequency, signal gain, orientation angle and the like, and is used for receiving environmental background electromagnetic radiation, and due to the arrangement of 90 degrees, the comparison antenna A2 can minimize electromagnetic field radiation of the motor M, and serves as a basis for signal distinguishing for subsequent differential coupling identification.

After sampling signals of various frequencies of the sampling antenna A1 and the comparison antenna A2 are obtained, the two signals are subjected to differential comparison in the same phase through a logic circuit, as shown in fig. 2, the amplitude of the comparison antenna frequency spectrum C-A2 is subtracted from the frequency corresponding to the sampling antenna frequency spectrum C-A1, and then a differential coupling frequency spectrum shown by a shaded part in the way can be obtained, wherein a differential coupling voltage identification point delta U-peak with the maximum amplitude is a signal point most relevant to the running of the motor M. It should be noted that there may be a plurality of differential coupling voltage identification points Δ U-peak, and at this time, the detection device needs to be moved to further check whether there is an interference signal of a nearby motor, for example, there is an independent cooling fan or an auxiliary motor for supplying oil and water inside the main driving motor.

Since the input current frequency of the motor is generally low, even if the motor is large in number of pole pairs, the electromagnetic radiation frequency is within 3000KHz, as shown in fig. 3, in this frequency range, it is exactly the long wave frequency region LW and the medium wave frequency region MW, which is why the operation of the motor is more disturbing to the radio. The LW in the long-wavelength frequency region is easy to generate surface wave diffraction due to low frequency and long wavelength, and the detection distance is too far to have discrimination, so that the LW is excluded. Therefore, in the initial test, the medium wave frequency region MW is selected firstly, the differential coupling voltage identification point delta U-peak signal strength is the highest, which is most beneficial to signal acquisition, but after multiple tests, the frequency of the section is found to be easily influenced by broadcast signals, especially when radio stations are relatively close, the radio station signals are stronger than the motor signals in certain measurement directions, so that the differential coupling identification method of the dual directional antenna fails, and the electromagnetic field radiation of the motor cannot be accurately measured. At the moment, for better applicability, a short wave frequency region SW with higher frequency is selected, a frequency doubling sampling principle that on-off type step signal electromagnetic radiation can be expanded on a corresponding Fourier integer level is utilized, a higher harmonic signal acquisition point Uac with higher frequency and a second signal amplitude is acquired, a radio noise region noise zone is avoided, for indoor use, short waves are not easy to penetrate through a building after being reflected by an ionized layer, therefore, a radio silence region clean zone above a radio noise cut-off frequency F0 is selected, the signal amplitude is not maximum at the moment, but the signal-to-noise ratio is strongest, the detection range is further narrowed, the detection accuracy is improved, interference is reduced when the frequency is higher, the motor radiation signal is also exponentially reduced, and the detection contrast is not increased. Of course, when used outdoors, this approach may be subject to interference and impact from short wave radio stations and cosmic radiation, but has been a relatively good technical route in general. In addition, in an outdoor scene, another solution is provided, the top end of the sampling antenna A1 is designed to be made of a metal conductive material, the sampling antenna A1 can be directly contacted with a metal exposed part of the motor when necessary, the electromagnetic signal of the motor can be directly measured by a detection device and a motor shell equipotential method, and the function of knowing the running state of the motor without disassembling the motor can also be achieved.

On the basis of the core principle, detection data can be displayed more visually through a series of circuits and an embedded system, the handheld design is convenient to move and use, meanwhile, the data can pass through mass transfer detection digital platforms such as WIFI and Bluetooth, a connecting wire is used as an edge sensor, the functions of the device are further integrated, fig. 4 is a typical internal structure principle of the detection device, a sampling antenna A1 collects electromagnetic signals of a motor, the levels of non-contact signals and contact signals are converted into mV levels through a signal conditioner B, then the levels and the levels of the non-contact signals and the contact signals enter a short-wave radio C together with a comparison antenna A2 to be demodulated, differentially coupled and the like, a higher harmonic signal collection point Uac is converted into an analog sound signal, for the analog signal part, a sound prompt with specific frequency can be generated by a loudspeaker G through a power amplifier D, the on-off and rotating speed change of the motor can be known qualitatively and visually according to the tone and the size of the sound, and the handheld detection device is suitable for technicians with abundant experience; to the digital signal part, the radio signal gets into embedded singlechip K and carries out the operation, and wherein the essential element passes through analog to digital converter J and changes into digital signal, carries out parameter display such as frequency, intensity for liquid crystal display H, and another part is then through wireless transmitter L, uses WIFI, bluetooth etc. to upload to the quality control platform, also can connect wireless earphone to use, is fit for more novice and quantitative detection and uses. The data and charging port F can also be used as an interface for USB wired data transmission, and can be used for charging the rechargeable lithium battery E, and the rechargeable lithium battery E can be used for supplying power to other modules. Wherein: circuits and embedded systems are state of the art.

In the external structure design of the detection device, as shown in fig. 5 (a) and (b), the sampling antenna 1 or A1 is exposed to facilitate both contact measurement and non-contact measurement, the main display screen 2 is a digital display area which mainly displays parameters such as signal intensity and signal frequency, and can also output motor state parameters such as on-off, rotation speed, acceleration, power and the like after calculation according to the motor parameter characteristics, and the auxiliary display screen 3 is an analog display area which qualitatively displays signal intensity or voltage level and the like. The cancel key 4 and the confirm key 9 can be used in cooperation with touch control of a display screen, and are used for switching various functions and improving stability of industrial use. Switch 5 is detection device's total switch, 6 trompil release sounds of loudspeaker cover, frequency modulation knob 7 can adjust sampling frequency through the rotation, typical numerical value is 3-30MHz, signal to noise ratio and sound size can be adjusted to gain knob 8, preceding shell 10 and back shell 13 should adopt engineering plastics, rubber or other non-metallic material, prevent that antenna A2 can not receive external signal than comparison, it is connected through set screw 11, the device reverse side sets up battery cover 12 and conveniently changes the battery, go out sound hole and reversal hole 15 after setting up from top to bottom, data and charging mouth 14 can be established in the below, external part should possess certain waterproof, prevent falling and dustproof characteristic, use with adaptation industry and outdoor high strength.

Variation of the present invention:

1) In addition to hand-held, desktop, rack-type, or as part of a system;

2) 2 or more similar comparison antennas are adopted;

3) And the display is performed by adopting incandescent lamps, fluorescent lamps, LED lamps, laser lamps and the like.

Claims

1. The utility model provides a motor running state detection device based on higher harmonic electromagnetic radiation which characterized in that: the short-wave radio comprises a sampling antenna (A1) and a comparison antenna (A2), wherein the sampling antenna (A1) is vertical to the 90-degree direction and is provided with the comparison antenna (A2) for receiving an environmental background electromagnetic radiation signal, the sampling antenna (A1) collects an electromagnetic signal of a motor and then converts the levels of a non-contact signal and a contact signal into mV level through a signal conditioner (B), the level of the non-contact signal and the level of the non-contact signal are then converted into mV level together with the environmental background electromagnetic radiation signal received by the comparison antenna (A2) to enter a short-wave radio (C) for demodulation and differential coupling, a higher harmonic signal collection point (Uac) is converted into an analog sound signal, the analog sound signal is output to a loudspeaker (G) through a power amplifier (D) to generate a sound prompt with specific frequency, and the on-off and rotating speed change of the motor are qualitatively and intuitively known according to the tone and size of the sound; or the short wave radio (C) inputs the signal into the embedded singlechip (K) for operation, and one part of the signal is converted into a digital signal through the analog-to-digital converter (J) and is transmitted to the liquid crystal display (H) for frequency and intensity parameter display; the other part is uploaded to a quality inspection platform by using WIFI and Bluetooth through a wireless transmitter (L) or is connected with a wireless earphone for use.

2. The device for detecting the operating condition of the motor based on the higher harmonic electromagnetic radiation according to claim 1, wherein: the parameters of the comparison antenna (A2) and the sampling antenna (A1) are the same, and the parameters comprise fixed frequency, signal gain and orientation angle.

3. The device for detecting the operating condition of the motor based on the higher harmonic electromagnetic radiation according to claim 1, wherein: the motor operation state detection device further includes:

a front housing (10) and a rear housing (13);

the main display screen (2) is a digital display area and is used for displaying signal intensity and signal frequency or outputting motor state parameters after calculation according to the characteristics of the motor parameters;

the display screen (3) is an analog display area and qualitatively displays the signal intensity or the voltage level;

the auxiliary cancel key (4) and the confirm key (9) are matched with a display screen for touch control use and are used for switching various functions, so that the use stability is improved;

the power switch (5) is a main power switch of the detection device;

a horn cover (6) having an opening for releasing sound;

a frequency-modulation knob (7) for adjusting the sampling frequency by rotation;

and a gain knob (8) for adjusting the signal-to-noise ratio and the sound size.

4. The device for detecting the operating condition of the motor based on the higher harmonic electromagnetic radiation according to claim 3, wherein: the front shell (10) and the rear shell (13) are made of engineering plastics, rubber or nonmetal materials except the engineering plastics and the rubber and are used for preventing the comparison antenna (A2) from receiving external signals.

5. The device for detecting the operating condition of the motor based on the higher harmonic electromagnetic radiation according to claim 3, wherein: preceding shell (10) and back shell (13) pass through set screw (11) and connect whole casing, set up battery cover (12) on the whole casing back and conveniently change the battery, go out sound hole and hole of falling (15) after setting up from top to bottom, the below sets up data and charges mouthful (14).

6. The device for detecting the operating condition of the motor based on the higher harmonic electromagnetic radiation according to claim 5, wherein: the data and charging port (F) serves as an interface for USB wired data transmission and simultaneously charges the rechargeable lithium battery (E).

7. A method for detecting the running state of a motor based on higher harmonic electromagnetic radiation, which adopts the device for detecting the running state of the motor based on higher harmonic electromagnetic radiation as claimed in any one of claims 1 to 6, and is characterized in that: firstly, in an industrial environment, a sampling antenna (A1) and a comparison antenna (A2) are close to a measured motor (M) in operation, the obtained sampling signals of the frequencies of the sampling antenna (A1) and the comparison antenna (A2) are subjected to differential comparison by a logic circuit, the amplitudes of the frequency spectrum (C-A2) of the comparison antenna are subtracted from the corresponding frequency of the frequency spectrum (C-A1) of the sampling antenna, and a differential coupling frequency spectrum is obtained, wherein the differential coupling voltage identification point (delta U-peak) with the maximum amplitude is the signal point most relevant to the operation of the motor (M).

8. The method for detecting the operating state of the motor based on the higher harmonic electromagnetic radiation according to claim 7, wherein: in the process, the detection device is moved to further check whether interference signals of the adjacent motors exist or not; and selecting a short wave frequency region (SW) with higher frequency, and acquiring a higher harmonic signal acquisition point (Uac) with higher frequency and secondary signal amplitude by utilizing a frequency doubling sampling principle that on-off type step signal electromagnetic radiation is expanded on a corresponding Fourier integer level series, so as to avoid a radio noise region (noise zone).

9. The method of claim 8, wherein the step of detecting the operating condition of the electrical machine comprises the steps of: when used indoors, a radio silence zone (clean zone) above the radio noise cut-off frequency (F0) is selected.

10. The method of claim 8, wherein the step of detecting the operating condition of the electrical machine comprises the steps of: when the device is used in an outdoor field, the top end of the sampling antenna (A1) is provided with a metal conductive material or is directly contacted with a metal exposed part of the motor, and the electromagnetic signal of the motor is directly measured by a detection device and a motor shell potential method, so that the function of knowing the running state of the motor without disassembling the motor is achieved.